Remove dynamic weather year parameter

This feature is still experimental and has some issues. Also,
increase texture_min_size to 64 px. The setting was initially
a conservative 16 so that the effect would not be noticable
for players who aren't using aniso/bi/trilinear filtering. This
isn't necessary now that texture_clean_transparent is disabled
by default.

Signed off by: Zeno, kwolekr

Conf.example: Update mgv5 mapgen params
Mgv7: Lava caves only below -256

Fix unused (and so, broken) enable_rollback_recording. This option must be reloaded at server loop but loaded when server starts, for data consistency (not a hot load variable)
ok @ShadowNinja

Conf.example: Add mgv7 cave1, cave2 noiseparams
Mgv7: Make skipping of mountain code relative to y=0 not water level
Mountain noise offset now -0.6 to compensate
Tune chance of large caves

Conf.example: Correct grammar and spelling. Shorten some lines. Move a few lines into correct sections. Remove finite liquid reference. Make indentation consistent

Increase indentation throughout file for clarity. Correct mistakes. Shorten lines. Make more consistent

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

If liquid_queue_purge_time == 0 then disable the queue size limiting and make this the default setting
Additionally, liquid_loop_max now defaults to 100000

Add format example to minetest.conf.example
Add Settings::setU16()
Throw exception on attempted access of NULL settings groups

Fix non coding style conforming glb_fontengine to g_fontengine
Fix fonts never been deleted due to grabbed to often

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

Since minetest has no mobs within the core anymore, I suppose these
settings and code should go. Any mod that uses `minetest.setting_getbool`
will work with no problem since the default return value is `false`.

Config settings:
profiling = true/false (gather statistics)
detailed_profiling = true/false (break mod times to callbacks)

Chat commands:
save_mod_profile saves current statistics in debug.txt and shows on console (on default loglevel)